January 29, 2013 AT 8:28 am

The Occidentalis Linux distribution for Raspberry Pi (and Raspbian as of Dec 2012) includes support for the DS18B20 1-wire temperature sensor. These sensors come in a small three pin package like a transistor and are accurate digital devices.

In this lesson, you will learn how to use a DS18B20 with the Raspberry Pi to take temperature readings.

Since the Raspberry Pi has no ADC (Analog to Digital Converter), it cannot directly use an analog temperature sensor like the TMP36, making the DS18B20 a good choice for temperature sensing.

Stepper motors fall somewhere in between a regular DC motor (Lesson 9) and a servo motor (Lesson 8]). They have the advantage that they can be positioned accurately, moved forward or backwards one ‘step’ at a time, but they can also rotate continuously.

In this lesson you will learn how to control a stepper motor using your Raspberry Pi and the same L293D motor control chip that you used with the DC motor in Lesson 9.

The Lesson will also show you how to use an alternative driver chip, the ULN2803.

For this project, it does not really matter if you use a L293D or a ULN2803. The lower cost of the ULN2803 and the four spare outputs, that you could use for something else, probably make it the best choice if you don’t have either chip.

The motor is quite low power and suffers less from the surges in current than DC motors and servos (which use DC motors). This project will therefore work okay powered from the 5V line of the Raspberry Pi, as long as the Pi is powered from a good supply of at least 1A.

This lesson describes how to control both the speed and direction of a DC motor using Python and a L293D chip. In Lesson 8, we used the Pi to generate pulses to control the position of a servo motor. In this lesson we use pulses to control the speed of a regular DC motor and the L293D motor control chip to reverse the direction of the current through the motor and hence the direction in which it turns.

This lesson describes how to control a single servo motor using Python. Servo motors are controlled by pulses of varying lengths. This requires fairly accurate timing. The Raspberry Pi has one pin that generates pulses in hardware, without having to rely on the operating system. Occidentalis includes an interface to make use of this pin for controlling a servo motor.

In this lesson we will explain how to install and use VNC on your raspberry Pi. This will allow you to see your Raspberry Pi’s desktop remotely in a graphical way, using the mouse as if you were sitting in front of your Pi.

Connecting to a Pi like this can save on desktop clutter, and the problem of having multiple keyboards and mice all over the place. It also means you can put your Pi somewhere else on the network, but still control it.

In this lesson you will learn how to remote control your Raspberry Pi over your local network using Secure Shell (SSH). A common reason for remote controlling your Pi from another computer us that you may be using your Pi solely to control some electronics and therefore not need a keyboard, mouse and monitor, other than for setting it up. It also can just save on desktop clutter, and the problem of having multiple keyboards and mice all over the place.

In this lesson you will learn how to remote control your Raspberry Pi with a console cable. The great advantage of connecting this way is that it can even supply the power for your Pi and you do not need keyboard, mouse or display attached to the Pi to log into it.

You will need to install terminal emulation software (ZOC) and also USB drivers for the Console Lead. ZOC is available for Mac and Windows and allows you to communicate through a serial port from your Mac or PC to another computer – in this case the Raspberry Pi.

The Raspberry Pi uses its built-in serial port to allow devices to connect to its console and issue commands just as if you were logged in.

In the next lesson, we will look at another way of doing much the same thing but over a local network using something called SSH.

In the first lesson of this series, we showed you how to prepare an SD card containing an operating system for your Raspberry Pi. In this lesson, we will show you how to setup your Raspberry Pi the first time you boot it up.

We do this using a tool called Raspi-Config that runs automatically the first time you boot your Raspberry Pi. This starts before the windowing system and so you have to use the cursor keys and Return key to navigate the menu system.

It is a bit like adjusting the BIOS settings on a PC, once you have things right, you probably won’t need it again.

We will start with the options that are most important and then look at some of the other options that you may wish to configure.

When you buy a Raspberry Pi, it may or may not be sold with an SD card. The SD card is important because this is where the Raspberry Pi keeps its operating system and is also where you will store your documents and programs.

Even if your Pi came with an SD card with the operating system on, it is a good idea to update it to the latest version, as improvements and bug fixes are going in all the time. Since putting the operating system onto an SD card wipes everything else off the card, it is worth considering using a USB flash drive for your documents, so that when you install a new version of the operating system, you dont’ have the complication of copying them off somewhere self before reformatting the SD card.

If your Pi did not come with an SD card then the minimum size you should get is 4GB, but buy a bigger SD card if you think you will need the space.
This lesson shows you how to create an SD card for your Raspberry Pi.